Distribution of alpha- and gamma-tocopherols within blood fractions of ruminants

This is a comparative study of alpha- and gamma-tocopherol levels in plasma, red blood cells, and in lipoprotein fractions, and their interrelationships with plasma cholesterol and total lipids were studied in camel, cattle, and in sheep. Plasma alpha- and gamma-tocopherol levels in cattle were significantly higher than in camel or sheep (P < 0.001 and P < 0.05). Erythrocytes of the three species contained similar amounts of both alpha- and gamma-tocopherol. Plasma tocopherols distributed equally between plasma lipoprotein fractions of camel and cattle, but sheep had significantly higher LDL/HDL tocopherol ratios than camel or cattle (P < 0.05). All species had similar plasma tocopherol to total lipid ratios, but varied in RBC-to-plasma tocopherol ratios where sheep had significantly the highest ratio (P < 0.05). Plasma cholesterol and total lipids were positively correlated with plasma alpha- and gamma-tocopherol in all species, and were negatively correlated with alpha-tocopherol in the erythrocytes. gamma-Tocopherol in red blood cells correlated with cholesterol and total lipids negatively in camel and positively in cattle. The camel's unique adaptations to dehydration and rehydration may not be related to deference in vitamin E distribution within blood fractions. Plasma cholesterol level is probably the main determinant of blood tocopherol concentration and distribution pattern.